What mood is established by the author in the beginning of the short story? Provide examples the author uses to establish this mood

In the beginning of the story, Connel uses the fog and noises associated with sea to build a mood of suspense and mystery.

You've good eyes," said Whitney, with a laugh," and I've seen you pick off a moose moving in the brown fall bush at four hundred yards, but even you can't see four miles or so through a moonless Caribbean night." "Nor four yards," admitted Rainsford. "Ugh! It's like moist black velvet."

An abrupt sound startled him. Off to the right he heard it, and his ears, expert in such matters, could not be mistaken. Again he heard the sound, and again. Somewhere, off in the blackness, someone had fired a gun three times.